A defect in the GALC gene causes Krabbe disease. Persons with this gene defect do not make enough of a substance called galactocerebroside beta-galactosidase (galactosylceramidase).
The body needs this substance to make myelin, the material that surrounds and protects nerve fibers. Without it, myelin breaks down, brain cells die, and nerves in the brain and other body areas do not work properly.
Krabbe disease can develop at various ages:
- Early-onset Krabbe disease appears in the first months of life. Most children with this form of the disease die before they reach age 2.
- Late-onset Krabbe disease begins in late childhood or early adolescence.
Krabbe disease is inherited, which means it is passed down through families. If both parents carry the defective gene related to this condition, each of their children has a 25% chance of developing the disease. (See: Autosomal recessive pattern)
This condition is very rare. It is most common among people of Scandinavian descent.